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(Page 2) <br />MINE ID # OR PROSPECTING ID #: M-1977-775 <br />INSPECTION DATE: March 77,~nm INSPECTOR'S INifIALS: AI A <br />OBSERVATIONS <br />This inspection was conducted to monitor the pneumatic backfilling of the 9360 Adit in compliance with Technical Revision <br />10, which was approved by the Division of Minerals and Geology. Homestake selected pneumatic backfilling because the adit <br />had several broken crossbars near the portal that had been supported with posts set in the middle of the adit. This prevented <br />access to more conventional equipment, like an LHD or Bobcat. Pneumatic backfilling only requires installation of a pipeline, <br />and personnel access is minimized. TR-10 is final closure and reclamation of the 9360 Adit, including: <br />Permanent sealing of the pressure measurement and tracer injection pipes placed within the concrete adit plug; <br />• Filling the 9360 adit from the adit plug to the entrance with pneumatically placed backfill (approximately 120 feet); <br />• Final reclamation and grading of the area near the entrance of the adit; and, <br />Revegetation of the entrance area. <br />The pipes through the adit plug had been grouted the previous day, March 26, 2002, with grouting verified by Mr. Mackenzie <br />Burnett, P.E. of Burnett Engineering, and Mr. Vernon Kelso of Homestake Mining Company. <br />This inspection verified the method of backfilling and observed the actual fill in place. The backfilling is conducted by blowing <br />3/," rock and 3/4' roadbase through 6" inside diameter PVC sewer pipe to approximately 20 feet from the adit plug. The <br />velocity of the rock being conducted through the pipeline is sufficient to carry the rock to the adit plug. Rock is delivered to <br />the site by a contract hauler in 25 ton end dump tractor-trailer trucks. The rock is loaded into a converted dump truck bed <br />using a John Deere 555 track loader. The dump truck bed meters the rock into the pneumatic feed hopper, an approximately <br />24" diameter cone. The pneumatic feed hopper is connected to a sweep that joins the air flow and the rock being fed into <br />the system. The rock is accelerated to approximately 80 to 100 feet per second by the volume and velocity of the air in the <br />pipeline. Air is supplied to the system by an Ingersol Rand 1600 air compressor. The entire system arrived at the site on a <br />40 foot low boy trailer. <br />Backfill in the mine assumes the angle of repose of the rock (estimated at approximately40°) with compaction at the point <br />of impact at least 100%, and the overall compaction estimated to be approximately 80% standard proctor. The backfill is <br />oaupying approximately 95% of the opening, with rods flowing around the posts, and being forced up between the cross bars <br />in some places. Overall the backfill is excellent. Please note: all angles and percentages are visually estimated. <br />The backfilling was completed March 29, 2002, and the portal area was graded and prepared for revegetation. This backfill <br />method is applicable to remote backfilling of hazardous openings, by pushing a pipe into the opening. <br />I & E Contact Address <br />NAME: Mr. AI Cox <br />OPERATOR: Garrick Management Group(~ <br />STREET: 6719 Academy Road NE •1't~, <br />CITY/STATE/ZIP: Alb~~nPrq~e, NM R71n9 <br />cc: ^ Mr. Jim Stevens <br />^ CE <br />^ BL <br />^ FS <br />^ HW <br />^ HMWMD (CH) <br />^ SE <br />^ WQCD (CH) <br />